Most projects of this SCOR grant will depend to varying degrees upon the availability of cultured and isolated synovial microenvironment components as well as on the availability of fresh and cultured synovial T cell preparations. Moreover, each human tissue, synovial fluid, or peripheral blood specimen will need to be logged in, processed, and in the case of tissue, portions frozen for immunohistology, portions prepared for light microscopy, and portions prepared for electron microscopy. Preparation and use of monoclonal antibodies are also required by many of the Center's investigators. In addition, Project 5 will use the MRL mouse model of arthritis and will require tissue sections for histopathology and in situ hybridization assays, monoclonal antibody technology, and eventually the techniques for growing murine synovial cells. In developing this application, it was decided that the most economical and efficacious approach to meet these needs for the entire program was to centralize these activities. The principal justification for this Core facility derives from the highly labor intensive nature of growing and characterizing synovial microenvironment components and also derives from Dr. Singer's special skills in performing these tasks. The Specific Aims of this Core Unit I are to culture synovial cells and to provide fresh samples of macrophages and T cells to investigators for functional studies, to establish a synovial tissue bank in order to provide fresh or frozen synovial tissue samples for studies, and to provide tissue sections to investigators performing in situ hybridization studies, immunofluorescent assays, or light microscopic analysis. This Core facility is designed to be an important source of tissue culture cells and tissue sections that will be available to all members of the Centers. Use of this facility appropriately will prevent needless duplication of effort and expense and will ensure uniformity of cell populations and tissues studied.